This invention relates generally to lamps and more specifically to safelight lamps used in darkrooms for photosensitive materials and the like.
Safelight lamps are commonly known in the art. A safelight is a lamp which emits filtered light of certain wavelengths making it safe to use in a darkroom with photosensitive and X-ray sensitive materials. The most common use of safelights is in the development of photographic negatives, X-Ray negatives, and the like.
Simple safelights are made by merely coating incandescent light bulbs with a colored filtering coating such as amber or red. Florescent light bulbs are also used as safelights by putting a filtering coating on the florescent light bulb. These coated bulbs are screwed or mounted into conventional light fixtures to create simple safelights.
These simple safelights operate the same as conventional lamps and have no special features directed to the unique requirements of working in a darkroom.
A second type of safelight is specifically designed for use in darkrooms. These safelights use a low wattage bulb, typically 7 to 15 watts, located inside a lamp housing. A safelight filter is mounted over the lamp opening in the housing and filters the light produced by the bulb making the device safe for use with photosensitive materials.
These safelights are specifically designed for use in darkrooms, however, the only advantage of these safelights is their ability to interchange different safelight filters. They have no other special features directed to the unique requirements of working in a darkroom.
Even these so called "safelights" are not completely safe to use when working with photosensitive and X-ray sensitive materials. Several additional safeguards typically must be taken to ensure light from the safelight does not damage or fog the photosensitive materials.
First, safelights must use very low wattage bulbs to reduce damage or fogging to photosensitive materials. Typically, safelights use only 7 to 15 watt bulbs. Second, safelights are normally kept at least four feet from the photosensitive materials to further reduce fogging. Third, for some materials, safelights can be used for only a brief period of time to limit fogging of the photosensitive film or material.
Because of these special requirements and other limitations, operating in a darkroom is often very inconvenient. The dim filtered light from the safelight barely illuminates the work area and does not illuminate other areas of the darkroom, i.e. in corners, under counters, on the floor, etc. If something is dropped or misplaced, it is difficult to find without turning on a white light and destroying the photosensitive materials.
Clearly, there exists a need for a new safelight which provides illumination in all locations of a darkroom, warns about over exposure to the safelight, and simplifies the operation of a typical darkroom.